<!doctype html> 
<html> 
<head> 
    <meta charset="utf-8"> 
    <title></title> 

    <style type="text/css">
.m{
	width: 100px;height: 100px;background: black;
}

    </style>
    <script type="text/javascript" src='jquery-1.9.1.min.js'></script>
</head>
<div></div>
<body>
<script type="text/javascript">

$().addClass();

function $(){

}
$.prototype.addClass = function(){

};

new $().addClass()

</script>
</body>
</html>